The present invention pertains to a chair, and to an office chair in particular.
Office chairs of the type under consideration include a vertical stand, provided with a plurality of radially outwardly extended feet having at the ends thereof rollers, a seat portion on that vertical stand and a back rest portion. The seat portion and the back rest portion are pivotable so that the chair, under the weight of the user can be adjusted to the posture of the user's body. The seat portion can be vertically adjustable.
In such known office chairs the inclination of the seat portion is mechanically adjustable. In order to adjust the seat portion to any desired inclined position one should loose the fastening means, adjust the angle of inclination of the seat portion and fasten the fastening means again. The same means can be applied to the adjustment of the back rest portion to any desired inclined position. Since such an adjustment is rather bothersome frequently in practice desired inclined positions of the seat portion and back rest portion are first preadjusted and then additionally modified.
With known office chairs the back rest portion is normally not-adjustable in respect to the seat portion and the back rest portion is pivotable rearwardly together with the seat portion. Such a combined pivoting motion of the back rest portion and the seat portion is usually performed against the force of a spring, which force is adjustable.